Anal incontinence after obstetric sphincter tears: incidence in a Norwegian county

Anal incontinence following obstetric anal sphincter injury: Is there a difference between subtypes? A systematic review

AIMS

Obstetric anal sphincter injury (OASI) is associated with long-term anal incontinence (AI). We aimed to address the following questions: (a) are women with major OASI (grade 3c and 4) at higher risk of developing AI when compared to women with minor OASI (grade 3a and 3b)? (b) is a fourth-degree tear more likely to cause AI over a third-degree tear?

METHODS

A systematic literature search from inception until September 2022. We considered prospective and retrospective cohort studies, cross-sectional and case-control studies without language restrictions. The quality was assessed by the Newcastle-Ottawa Scale and the Joanna Briggs Institute critical appraisal checklist. Risk ratios (RRs) were calculated to measure the effect of different grades of OASI.

RESULTS

Out of 22 studies, 8 were prospective cohort, 8 were retrospective cohort, and 6 were cross-sectional studies. Length of follow-up ranged from 1 month to 23 years, with the majority of the reports (n = 16) analysing data within 12-months postpartum. Third-degree tears evaluated were 6454 versus 764 fourth-degree tears. The risk of bias was low in 3, medium in 14 and high in 5 studies, respectively. Prospective studies showed that major tears are associated with a twofold risk of AI for major tears versus minor tears, while retrospective studies consistently showed a risk of fecal incontinence (FI) which was two- to fourfold higher. Prospective studies showed a trend toward worsening AI symptoms for fourth-degree tears, but this failed to reach statistical significance. Cross-sectional studies with long-term (≥5 years) follow-up showed that women with fourth-degree tear were more likely to develop AI, with an RR ranging from 1.4 to 2.2. Out of 3, 2 retrospective studies showed similar findings, but the follow-up was significantly shorter (≤1 year). Contrasting results were noted for FI rates, as only 5 out of 10 studies supported an association between fourth-degree tear and FI.

CONCLUSIONS

Most studies investigate bowel symptoms within few months from delivery. Data heterogeneity hindered a meaningful synthesis. Prospective cohort studies with adequate power and long-term follow-up should be performed to evaluate the risk of AI for each OASI subtype.

Language barrier as a risk factor for obstetric anal sphincter injury - A case-control study

INTRODUCTION

The incidence of grade 3-4 perineal tears, also known as obstetric anal sphincter injury (OASI), is reported to be between 0.5 and 2.5%. Beyond the medico-economic burden, the consequences of OASI on a woman's emotional, psychological, sexual, and physical wellbeing are considerable. Among the various risk factors of OASI, few data are available about the impact of a language barrier on its incidence.

MATERIAL AND METHODS

We conducted a case-control study to evaluate the effect of language barriers on the risk of OASI comparing 171 women with OASI and 163 matched controls. The matched criteria included ethnicity, age, previous vaginal delivery, delivery mode, prophylactic episiotomy and birthweight. Patients' characteristics were compared and crude ORs and 95% CIs estimated using unadjusted logistic models. Multivariate analysis was performed with recognized potential confounders.

RESULTS

All of the cases had grade 3 tears. Language barrier was a determinant factor of OASI with an OR of 3.32 [1.36-8.90], p = 0.01. Other risk factors were occipito-posterior delivery, African origin and prolonged labor duration (OR 6.33, 95% CI: 2.04-27.78, p = 0.004, OR 1.85, 95% CI: 1.08-3.19, p = 0.03 and OR 1.03, 95% CI: 1.01-1.05, p = 0.004, respectively).

CONCLUSION

Our data suggest that language barrier is an independent risk factor of OASI. Physicians and midwives should attempt to identify patients with a language barrier during prenatal visits. Education about simple terms used during delivery could decrease the incidence of this complication.

Can ultrasound 10 days after obstetric anal sphincter injury predict anal incontinence at long-term follow-up?

INTRODUCTION AND HYPOTHESIS

The objective was to investigate whether endoanal ultrasound (EAUS) performed 10 days after a primary repaired obstetric anal sphincter injury (OASIS) can predict the severity of anal incontinence (AI) in the long term.

METHODS

This prospective cohort study included women with a primary repaired 3b-degree tear, 3c-degree tear or fourth-degree tear at Aarhus University Hospital, Denmark, from 1 September 2010 to 31 May 2011. Clinical assessment and EAUS were performed on day 2, day 10, and day 20 after delivery. Functional outcomes were assessed using a questionnaire at the time of all clinical visits and at the long-term follow-up, 7 years after delivery. AI was graded according to the Wexner score and EAUS defects were graded according to the Starck score.

RESULTS

Ninety-six out of 99 women consented to participate. Five women had a secondary sphincter repair and were subsequently excluded from follow-up. Fifty-seven women underwent both EAUS 10 days after delivery and answered the long-term follow-up questionnaire. Median follow-up time was 7.7 years (IQR 7.4-7.8). Mean Wexner score was 4.4 ± 4.8 10 days after delivery and 2.5 ± 2.8 at follow-up; thus, the Wexner score improved over time (p = 0.01). Ultrasound sphincter defects were found in 82.6% of the women. Mean Starck score was 3.0 ± 1.8. The risk of AI was 0% (95% CI 0.0-30.8) if the Starck score was 0. No correlation was found between the Starck score and the Wexner score at follow-up.

CONCLUSIONS

We found that performing EAUS in the puerperium following OASIS has limited value in predicting long-term AI.

Anal incontinence and unrecognized anal sphincter injuries after vaginal delivery- a cross-sectional study in Norway

Background

Aim of the study was to estimate the prevalence of postpartum anal incontinence among women who delivered vaginally, and to assess the extent to which obstetric injuries to the anal sphincters are missed.

Methods

All women (both primiparous and multiparous) who delivered vaginally and received any kind of sutures in the perineal area at Innlandet Hospital Trust Elverum in Norway between January 1, 2015 and June 30, 2016 were invited to answer a questionnaire on St. Mark’s incontinence score and to participate in a clinical examination of the pelvic floor including endoanal sonography.

Results

In total 52,3% (n = 207) of the 396 invited women participated in the study. Mean St. Mark’s score was 1.8 points (95% CI 1.4 to 2.1) at examination 14 months (mean) postpartum, and none of the participants suffered from weekly fecal leakage. Fecal urgency affected 11.7% (95% CI 7.1 to 16.3) of the participants, and 8.7% (95%CI 5.1 to 12.8) had weekly involuntary leakage of flatus. Nine women (9.3%, 95% CI 4.1 to 15.5) had a previously undetected third degree obstetric anal sphincter injury.

Conclusion

The prevalence of anal incontinence among women who have delivered vaginally and received sutures due to 1st and 2nd degree perineal lacerations is low. Some obstetric anal sphincter injuries remain unrecognized at the time of delivery, but the symptoms of anal incontinence due to these injuries are in the lower half of the St. Mark’s incontinence score. Women with persistent symptoms like fecal urgency or leakage of gas and/or feces should be referred to evaluation by a colorectal surgeon in order to achieve optimal treatment.

Secondary sphincter repair for anal incontinence following obstetric sphincter injury: functional outcome and quality of life at 18 years of follow-up

AIM

Secondary sphincter repair has been the conventional management of anal incontinence (AI) when a structural defect in the sphincter is recognized. However, disappointing long-term results have contributed to a tendency towards an increasing use of alternative treatment methods. This study aimed to assess the long-term functional outcomes following a secondary sphincter repair in women with AI after obstetric sphincter injury.

METHOD

This is a questionnaire study of women who underwent a secondary sphincter repair in Denmark between January 1990 and December 2005. Patients were identified through the Danish National Patient Registry. Functional outcomes were assessed by a self-administered questionnaire in 2010 and 2018. Primary outcomes were Wexner and St. Mark's scores. Impact on quality of life was assessed using the Fecal Incontinence Quality of Life Scale.

RESULTS

Functional outcome was assessed in 370 women in 2010 and 255 women in 2018. At 18.3 [interquartile range (IQR 15.0-22.0)] years of follow-up, the mean ± SD Wexner score was 8.8 ± 4.8 and the mean St. Mark's score was 11.7 ± 5.0. Flatus incontinence was the most frequent symptom, reported by 97%. Incontinence for liquid and solid stools was reported by 75% and 54%, respectively. There were no significant changes in incontinence frequencies over time. Women with a Wexner score of ≥ 9 had a significantly lower quality of life score in all domains than did women with a Wexner score of < 9 (P < 0.001).

CONCLUSION

At long-term follow-up, few patients are fully continent following a secondary sphincter repair. However, it appears that the functional results remain stable at very long-term follow-up.

Long-term outcome of sphincteroplasty with separate suturing of the internal and the external anal sphincter

Background

Sphincteroplasty is one of the treatment options for anal incontinence following obstetric injury. The aim of the study was to evaluate the long-term effect of sphincteroplasty with separate suturing of the internal and the external anal sphincter on anal continence.

Methods

A retrospective study was conducted on women who had sphincteroplasty for treatment of anal incontinence following obstetric injury. Women operated between January 1, 2011 and December 31, 2014 at Sykehuset Innlandet Hospital Trust Hamar, were invited to answer a questionnaire and participate in a clinical examination, including endoanal sonography.

Results

111 (86.7%) women participated. Median postoperative follow-up was 44.5 months, and 63.8% of the participants experienced an improvement of at least three points in the St. Mark’s incontinence score. Fecal urgency and daily fecal leakage persisted in 39.4% and 6.4% of the participants, respectively. The internal anal sphincter improvement persisted in 61.8% of the participants, and there was a median reduction of their St. Mark’s score of 6.0 points between the preoperative value and the value at long-term follow-up. There was no significant change in the St. Mark’s score of patients with persistent dehiscence of the internal anal sphincter.

Conclusions

Sphincteroplasty, with separate suturing of the internal sphincter resulted in continence for stool maintained for at least 3 years in the majority of the patients, while there was an improvement in continence in nearly two-thirds.

Factors associated with obstetric anal sphincter injuries in midwife-led birth: A cross sectional study

INTRODUCTION

Obstetric anal sphincter injurie (OASI) in vaginal births are a serious complication, and are associated with maternal morbidity. Focus on modifiable factors in midwives clinical skills and competences contributing to prevent the occurrence of OASI are essential. The objective of this study was to investigate the association between OASI and factors related to midwife-led birth such as manual support of perineum, active delivery of baby's shoulders, maternal birth position, and pushing and breathing techniques in second stage of labour.

METHODS

A prospective cross sectional study including primiparous (n = 129) and multiparous (n = 628) women in midwife-led non-instrumental deliveries with OASI (n = 96) or intact perineum (n = 661). Data were collected in a university hospital in Norway with two different birth settings: an alongside midwife-led unit with approximately 1500 births per year and an obstetrical unit with approximately 3500 births per year. In midwife-led births, there were a total of 2.6% OASI and 18.9% intact perineum.

RESULTS

The sample consisted of 757 women, 12.7% suffered OASI and 87.3% of participating women had an intact perineum. This selected sample compares the most serious outcome (OASI), and the optimal outcome (intact perineum).In primiparous women, 61 women suffered OASI and 68 women had intact perineum, while for multipara women, 35 women suffered OASI and 593 women had intact perineum. There was an increased risk of OASI if women actively pushed when the head was crowning compared to breathing the head out (adjusted OR: 3.10; 95% CI: 1.75 to 5.47). The maternal birth position associated with the lowest risk of OASI was kneeling position (adjusted OR: 0.15; 95% CI: 0.03 to 0.70), supine maternal birth position (adjusted OR: 2.52; 95% CI: 1.04 to 4.90) and oxytocin augmentation more than 30 min in second stage (OR: 1.93; 95% CI: 1.68 to 15.63) were associated with an increased risk of OASI, when adjusting for maternal, foetal, and obstetric factors.

CONCLUSION

Our study suggests that actively pushing when the baby's head is crowning, a supine maternal birth position and oxytocin augmentation more than 30 min in second stage, were associated with increased risk of OASI when compared to intact perineum. A kneeling maternal birth position was associated with a decreased risk of OASI.

Fetal head size and effect of manual perineal protection

OBJECTIVE

The aim of this study was to evaluate whether a previously identified modification of Viennese method of perineal protection remains most effective for reduction of perineal tension in cases with substantially smaller or larger fetal heads.

METHODS

A previously designed finite element model was used to compare perineal tension of different modifications of the Viennese method of perineal protection to "hands-off" technique for three different sizes of the fetal head. Quantity and extent of tension throughout the perineal body during vaginal delivery at the time when the suboccipito-bregmatic circumference passes between the fourchette and the lower margin of the pubis was determined.

RESULTS

The order of effectiveness of different modifications of manual perineal protection was similar for all three sizes of fetal head. The reduction of perineal tension was most significant in delivery simulations with larger heads. The final position of fingers 2cm anteriorly from the fourchette (y = +2) consistently remains most effective in reducing the tension. The extent of finger movement along the anterior-posterior (y-axis) contributes to the effectiveness of manual perineal protection.

CONCLUSION

Appropriately performed Viennese manual perineal protection seems to reduce the perineal tension regardless of the fetal head size, and thus the method seems to be applicable to reduce risk of perineal trauma for all parturients.

Wnt-β Catenin Signaling Pathway: A Major Player in the Injury Induced Fibrosis and Dysfunction of the External Anal Sphincter

Wnt-β catenin is an important signaling pathway in the genesis of fibrosis in many organ systems. Our goal was to examine the role of Wnt pathway in the external anal sphincter (EAS) injury-related fibrosis and muscle dysfunction. New Zealand White female rabbits were subjected to surgical EAS myotomy and administered local injections of either a Wnt antagonist (sFRP-2; daily for 7 days) or saline. Anal canal pressure and EAS length-tension (L-T) were measured for 15 weeks after which the animals were sacrificed. Anal canal was harvested and processed for histochemical studies (Masson trichrome stain), molecular markers of fibrosis (collagen and transforming growth factor-β) and immunostaining for β catenin. Surgical myotomy of the EAS resulted in significant impairment in anal canal pressure and EAS muscle L-T function. Following myotomy, the EAS muscle was replaced with fibrous tissue. Immunostaining revealed β catenin activation and molecular studies revealed 1.5–2 fold increase in the levels of markers of fibrosis. Local injection of sFRP-2 attenuated the β catenin activation and fibrosis. EAS muscle content and function was significantly improved following sFRP-2 treatment. Our studies suggest that upregulation of Wnt signaling is an important molecular mechanism of injury related EAS muscle fibrosis and sphincter dysfunction.

Episiotomy: What angle do you cut to the midline?

OBJECTIVE

Although episiotomies are the commonest obstetric procedure performed the technique of performing one varies amongst obstetricians and midwives. The angle of episiotomy to the midline in particular has been shown to influence the risk of developing obstetric anal sphincter injuries (OASIS). In order to identify the differences in technique and to identify targets for training we undertook a practice survey of episiotomies to analyse the differences in technique between grades of obstetricians and midwives.

STUDY DESIGN

A prospective practice survey of staff working on delivery suite in a tertiary referral unit with 9000 deliveries/year was conducted between 01/10/2014 to 01/03/2015. Each participant was provided with a pictoral representation of a perineum and a pair of standard episiotomy scissors and asked to perform an episiotomy as per their usual practice. The profession and grade of each participant was recorded along with information regarding the incision including the angle to the midline, length of incision and lateral starting distance from the midline. One way ANOVA (unrelated) was used to perform statistical analysis using IBM SPSS v23.

RESULTS

101 staff members participated in the practice survey including 63 midwives, 9 junior trainees, 15 senior trainees and 14 consultants. The mean angle of incision to the midline of episiotomies was 47°, 51°, 66° and 77° for midwives, junior trainees, senior trainees and consultants respectively. The mean angle of incision performed by midwives was significantly different to senior trainees (p>0.01) and consultants (p<0.01). 45% of all episiotomies undertaken by midwives were done at an angle <45° to the midline, compared to 7% by senior trainees and none by consultants.

CONCLUSIONS

This study identified clear deficiencies in the performance of episiotomies amongst obstetric trainees and midwives. Both midwives and obstetric trainees need to improve their technique if episiotomies are going to influence the incidence of OASIS and, more importantly the development of faecal incontinence. These results should be used to inform future training programmes to reduce the risks of OASIS.

Double-blind randomised controlled trial of percutaneous tibial nerve stimulation versus sham electrical stimulation in the treatment of faecal incontinence: CONtrol of Faecal Incontinence using Distal NeuromodulaTion (the CONFIDeNT trial)

BACKGROUND

Faecal incontinence (FI) is a common condition which is often under-reported. It is distressing for those suffering from it, impacting heavily on their quality of life. When conservative strategies fail, treatment options are limited. Percutaneous tibial nerve stimulation (PTNS) is a minimally invasive outpatient treatment, shown in preliminary case series to have significant effectiveness; however, no randomised controlled trial has been conducted.

OBJECTIVES

To assess the effectiveness of PTNS compared with sham electrical stimulation in the treatment of patients with FI in whom initial conservative strategies have failed.

DESIGN

Multicentre, parallel-arm, double-blind randomised (1 : 1) controlled trial.

SETTING

Eighteen UK centres providing specialist nurse-led (or equivalent) treatment for pelvic floor disorders.

PARTICIPANTS

Participants aged > 18 years with FI who have failed conservative treatments and whose symptoms are sufficiently severe to merit further intervention.

INTERVENTIONS

PTNS was delivered via the Urgent(®) PC device (Uroplasty Limited, Manchester, UK), a hand-held pulse generator unit, with single-use leads and fine-needle electrodes. The needle was inserted near the tibial nerve on the right leg adhering to the manufacturer's protocol (and specialist training). Treatment was for 30 minutes weekly for a duration of 12 treatments. Validated sham stimulation involved insertion of the Urgent PC needle subcutaneously at the same site with electrical stimulation delivered to the distal foot using transcutaneous electrical nerve stimulation.

MAIN OUTCOME MEASURES

Outcome measures were assessed at baseline and 2 weeks following treatment. Clinical outcomes were derived from bowel diaries and validated, investigator-administered questionnaires. The primary outcome classified patients as responders or non-responders, with a responder defined as someone having achieved ≥ 50% reduction in weekly faecal incontinence episodes (FIEs).

RESULTS

In total, 227 patients were randomised from 373 screened: 115 received PTNS and 112 received sham stimulation. There were 12 trial withdrawals: seven from the PTNS arm and five from the sham arm. Missing data were multiply imputed. For the primary outcome, the proportion of patients achieving a ≥ 50% reduction in weekly FIEs was similar in both arms: 39 in the PTNS arm (38%) compared with 32 in the sham arm (31%) [odds ratio 1.28, 95% confidence interval (CI) 0.72 to 2.28; p = 0.396]. For the secondary outcomes, significantly greater decreases in weekly FIEs were observed in the PTNS arm than in the sham arm (beta -2.3, 95% CI -4.2 to -0.3; p = 0.02), comprising a reduction in urge FIEs (p = 0.02) rather than passive FIEs (p = 0.23). No significant differences were found in the St Mark's Continence Score or any quality-of-life measures. No serious adverse events related to treatment were reported.

CONCLUSIONS

PTNS did not show significant clinical benefit over sham electrical stimulation in the treatment of FI based on number of patients who received at least a 50% reduction in weekly FIE. It would be difficult to recommend this therapy for the patient population studied. Further research will concentrate on particular subgroups of patients, for example those with pure urge FI.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN88559475.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 77. See the NIHR Journals Library website for further project information.

Anal incontinence, urinary incontinence and sexual problems in primiparous women - a comparison between women with episiotomy only and women with episiotomy and obstetric anal sphincter injury

Background

Obstetric anal sphincter injuries (OASIS) might cause anal incontinence (AI) and sexual dysfunction, and might be associated with urinary incontinence (UI). Episiotomy has been identified both as a risk and a protective factor of OASIS. Lately, episiotomies with specific characteristics have shown to be protective against the risk of OASIS. However, little is known about episiotomy characteristics and pelvic floor dysfunction. This study investigates AI, UI, and sexual problems in primiparous women with episiotomy, comparing women with and without OASIS. Associations between episiotomy characteristics and AI, UI, and sexual problems were assessed.

Methods

This is a matched case–control study investigating 74 women with one vaginal birth, all with an episiotomy. Among these, 37 women sustained OASIS and were compared to 37 women without OASIS. The two groups were matched for vacuum/forceps. AI, UI and sexual problem symptoms were obtained from St. Mark’s scoring-tool and self-administered questionnaires. The episiotomy characteristics were investigated and results assessed for the whole group.

Results

The mean time from birth was 34.5 months (range1.3-78.2) for those with OASIS and 25.9 months (range 7.0-57.4) for those without OASIS, respectively. More women with OASIS reported AI: 14 (38%) vs. 3 (8%) p = 0.05 (OR 4.66, 95% CI 1.34-16.33) as well as more problem with sexual desire p = 0.02 (OR 7.62, 95% CI 1.30-44.64) compared to women without OASIS. We found no association between episiotomy with protective characteristics and dysfunctions.

Conclusion

Women with OASIS had more AI and sexual problems than those without OASIS. Episiotomy characteristics varied greatly between the women. Episiotomy with protective characteristics was not associated with increased dysfunctions. OASIS should be avoided, and correct episiotomy used if indicated.

Prevalence and Risk Indicators for Anal Incontinence among Pregnant Women

The aim of this study was to assess the prevalence and risk factors of anal incontinence in an unselected pregnant population at second trimester. A survey of pregnant women attending a routine ultrasound examination was conducted in a university hospital in Oslo, Norway. A questionnaire consisting of 105 items concerning anal incontinence (including St. Mark's score), urinary incontinence, medication use, and comorbidity was posted to women when invited to the ultrasound examination. Results. Prevalence of self-reported anal incontinence (St. Mark's score ≥ 3) was the lowest in the group of women with a previous cesarean section only (6.4%) and the highest among women with a previous delivery complicated by obstetric anal sphincter injury (24.4%). Among nulliparous women the prevalence of anal incontinence was 7.7% and was associated to low educational level and comorbidity. Prevalence of anal incontinence increased with increasing parity. Urinary incontinence was associated with anal incontinence in all parity groups. Conclusions. Anal incontinence was most frequent among women with a history of obstetric anal sphincter injury. Other obstetrical events had a minor effect on prevalence of anal incontinence among parous women. Prevention of obstetrical sphincter injury is likely the most important factor for reducing bothersome anal incontinence among fertile women.

Sphincter training or anal injections of dextranomer for treatment of anal incontinence: a randomized trial

OBJECTIVE

The objective is to test if the injection of a bulking agent in the anal canal is superior to sphincter training with biofeedback in the treatment of anal incontinence.

BACKGROUND

Anal incontinence is traditionally treated with conservative measures, such as pads and constipating medicine. If this fails, sphincter training with biofeedback is often offered before more advanced surgical procedures are considered. The injection of a bulking agent in the anal canal is a relatively new and promising treatment option.

METHODS

In a randomized, controlled, evaluator-blinded trial, 126 adult patients with anal incontinence were randomly assigned to a transanal, submucosal injection of 4 x 1 mL of dextranomer in hyaluronic acid or to sphincter training with biofeedback. The primary outcome was severity of incontinence, evaluated by St Mark's score for incontinence (0 = continence to 24 = complete incontinence) assessed at 2 years after the start of treatment. A mixed models analysis was applied.

RESULTS

Of the 126 participants, 64 patients were randomly assigned to anal injections, and among them the mean St Mark's score improved from 12.9 (95% CI: 11.8-14.0) at baseline to 8.3 (95% CI: 6.7-9.8) at the end of follow up. Among the 62 patients who were assigned to sphincter training with biofeedback, there was a corresponding improvement in St Mark's score from 12.6 (95% CI: 11.4-13.8) to 7.2 (95% CI: 7.2-8.8). Comparisons of St Mark's scores between the groups showed no differences in effect between treatments.

CONCLUSION

The efficacy of anal injections and biofeedback in treating anal incontinence did not differ in this randomized, single-blinded, controlled trial.

Episiotomy characteristics and risks for obstetric anal sphincter injuries: a case-control study

Objectives

To investigate the association between the geometrical properties of episiotomy and obstetric anal sphincter injuries (OASIS) because episiotomies angled at 40–60° are associated with fewer OASIS than episiotomies with more acute angles.

Design

Case–control study.

Setting

University Hospital of North Norway, Tromsø and Nordland Hospital, Bodø, Norway.

Sample

Seventy-four women who had one vaginal birth and episiotomy. Cases (n = 37) have sustained OASIS at birth, while controls (n = 37) had not. The groups were matched for instrumental delivery.

Methods

Two groups of women with history of only one vaginal birth were compared. Episiotomy scar was identified and photographed and relevant measures were taken. Data were analysed using conditional logistic analysis.

Main outcome measures

Mean episiotomy angle, length, depth, incision point.

Results

The risk of sustaining OASIS decreased by 70% (odds ratio [OR] 0.30; 95% CI 0.14–0.66) for each 5.5-mm increase in episiotomy depth, decreased by 56% (OR 0.44; 95% CI 0.23–0.86) for each 4.5-mm increase in the distance from the midline to the incision point of the episiotomy, and decreased by 75% (OR 0.25; 95% CI 0.10–0.61) for each 5.5-mm increase in episiotomy length. Lastly, there was no difference in mean angle between groups but there was a “U-shaped” association between angle and OASIS (OR 2.09; 95% CI 1.02–4.28) with an increased risk (OR 9.00; 95% CI 1.1–71.0) of OASIS when the angle was either smaller than 15°or >60°.

Conclusion

The present study showed that scarred episiotomies with depth > 16 mm, length > 17 mm, incision point > 9 mm lateral of midpoint and angle range 30–60° are significantly associated with less risk of OASIS. Shrinkage of tissue must be considered.

Incidence of obstetric anal sphincter injuries after training to protect the perineum: cohort study

OBJECTIVE

To compare the incidence of obstetric anal sphincter injuries (OASIS) in two time periods, before and after implementing a training programme for improved perineal support aimed at reducing the incidence of obstetric anal sphincter injuries. The secondary aim was to study incidence of obstetric anal sphincter injuries in subgroups defined by risk factors for OASIS.

DESIGN

Population-based cohort study.

SETTING

University hospital setting in Oslo, Norway.

PARTICIPANTS

Two cohorts of all delivering women in the largest hospital in Norway during two time periods (2003-2005 and 2008-2010) were studied. After excluding caesarean sections and preterm deliveries (< week 32), the study population consisted of 31 709 deliveries, among which 907 women were identified with obstetric anal sphincter injury.

PRIMARY AND SECONDARY OUTCOME MEASURES

Incidence of OASIS in two time periods. Maternal, obstetrical and foetal risk factors for OASIS were collected from the hospital obstetric database. Univariate analyses and multivariate logistic regression analyses, presenting adjusted ODs for OASIS, were performed.

RESULTS

The OASIS incidence was significantly reduced by 50%, from 4% (591/14787) in the first time period to 1.9% (316/16 922) in the second. This reduction could not be explained by changes in population characteristics or OASIS risk factors during the study years. The reduction of incidence of OASIS between the two study periods was consistent across subgroups of women; regardless of parity, delivery method and infant birth weight.

CONCLUSIONS

A marked reduction in the incidence of OASIS was observed in all studied subgroups of women after implementing the training programme for perineal protection. Further, this reduction could not be explained by the differences in patient characteristics across the study period. These findings indicate that the training programme with improved perineal protection markedly reduced the risk of OASIS.

Impaired rectal sensation at anal manometry is associated with anal incontinence one year after primary sphincter repair in primiparous women

PURPOSE

This study investigates the association between endoanal ultrasonography and anorectal manometry in relation to anal incontinence after primary repair of obstetric sphincter injury in primiparous, premenopausal women.

METHODS

The study population of this nested case-control study comprised 108 women who had previously been part of a randomized controlled trial comparing immediate with delayed primary repair of obstetric sphincter injuries, and who had been evaluated by anorectal manometry and endoanal ultrasound 1 year after their repair. Twenty cases and 88 controls were defined. Cases were defined as having a score greater than 2 on the Pescatori incontinence scale. Controls had a score of 2 or less. Ten obstetric, 9 ultrasonographic, and 7 manometric variables were studied.

RESULTS

Of the manometric variables, volume of first sensation and volume of first urge proved to be associated with anal incontinence at univariate statistical analysis. Volume of first sensation remained independently associated with anal incontinence after multivariate analysis. In addition, age, degree of tear, duration of second stage of labor, and a distal scar at ultrasound proved to be independently associated with anal incontinence.

CONCLUSIONS

Impaired rectal sensation at anorectal manometry and a distal scar at endoanal ultrasonography are associated with anal incontinence 1 year after primary sphincter repair in primiparous women. Additional studies need to evaluate whether these findings are associated with increased risk of anal incontinence in women that are continent 1 year after primary repair.

Onset and risk factors for fecal incontinence in a US community

OBJECTIVES

The natural history of fecal incontinence (FI) in community subjects is uncertain and the onset rate is unknown. The aim of the study is to estimate the prevalence, new-onset rate, and risk factors for FI in community subjects.

METHODS

A random sample of 2,400 community subjects aged > or =50 years was surveyed in 1993, using a validated questionnaire. Responders were recontacted in 2003. FI was defined as self-reported problems with leakage of stool. Onset rate was calculated as the proportion of subjects without FI who became new cases. Logistic regression models were constructed to identify predictive factors for developing FI and changes in bowel habit associated with the onset of FI.

RESULTS

Overall, 1,540 (64%) subjects responded to the initial survey, and 674 (44%) of them responded to the second survey a median of 9 (8.8-9.5) years later. The prevalence of FI in the first survey was 15.3% (13.4-17.3%). In the second survey, 37 reported incident FI; thus, the onset rate of FI was 7.0% (5.0-9.6) per 10 years. Predictive factors at baseline for the onset of FI were self-reported diarrhea (odds ratio (OR)=3.8 (1.5, 9.4)), incomplete evacuation (OR=3.4 (1.2, 9.8)), and pelvic radiation (OR=5.1 (1.01, 25.9)). Development of urgency was the primary predictor among the set of predictors reflecting changes in bowel symptoms that were associated with the onset of FI (OR=24.9 (10.6, 58.4)).

CONCLUSIONS

The onset rate of FI is approximately 7% per 10 years in community subjects aged > or =50 years. Prevention may be possible if bowel habit is appropriately managed in high-risk individuals.

Immediate or delayed repair of obstetric anal sphincter tears-a randomised controlled trial

OBJECTIVE

To investigate if an 8- to 12-hour time delay of primary repair affects anal incontinence at 1-year follow up.

DESIGN

Randomised controlled trial.

SETTING

University hospital in Sweden.

POPULATION

A total of 165 women diagnosed with a third- to fourth-degree perineal tear.

METHODS

The participants were randomised to immediate or delayed (8- to 12-hour delay) end-to-end repair; 78 were allocated to immediate operation and 87 to a delayed repair. An incontinence and pelvic floor symptom questionnaire was completed by the participants at baseline and at 6- and 12-month follow up.

MAIN OUTCOME MEASURES

Anal incontinence measured by the validated Pescatori incontinence score.

RESULTS

A total of 161 (98%) and 155 (94%) women completed the two follow-up questionnaires. There was no significant difference in anal incontinence between the groups. There were no significant differences in pelvic floor symptoms between the groups. A multivariate proportional odds model revealed that increasing maternal age was significantly associated with both increased symptoms of faecal urgency and inability to discriminate flatus from faeces.

CONCLUSION

Delayed repair provided the same functional outcome at 1-year follow up. Delaying the repair should thus not be recommended routinely, but can be an alternative under special circumstances when appropriate surgical expertise is not readily available.

Trends in major modifiable risk factors for severe perineal trauma, 1996-2006

OBJECTIVE

To examine what effect the major modifiable risk factors for severe perineal trauma have had on the rates of this trauma over time.

METHODS

A retrospective observational cohort study of singleton vaginal deliveries taken from a perinatal database for the period 1996 through 2006.

RESULTS

A total of 46,239 singleton vertex vaginal deliveries met the inclusion criteria. Major risk factors for severe perineal trauma were increased maternal age (odds ratio [OR] 1.28, 95% confidence interval [CI] 1.1-1.5), non-African American ethnicity (OR 1.5, 95% CI 1.3-1.7), nulliparity (OR 4.8, 95% CI 4.11-5.6), fetal birth weight (OR 2.2, 95% CI 1.9-2.4), forceps (OR 8.3, 95% CI 5.4-10.8), vacuum (OR 2.9, 95% CI 1.9-4.4), and midline episiotomy (OR 5.7, 95% CI 5.0-6.4). Evaluation of the changes in rates of these factors over the study period revealed that the decline in the rates of episiotomy and the use of forceps accounted for a reduction in severe lacerations of more than 50%.

CONCLUSION

Reduction of severe perineal trauma by restricted use of the 2 modifiable clinical variables, episiotomy and forceps, is evident over time.

Obstetric anal sphincter injury: incidence, risk factors, and management

BACKGROUND AND AIMS

Obstetric sphincter damage is the most common cause of fecal incontinence in women. This review aimed to survey the literature, and reach a consensus, on its incidence, risk factors, and management.

METHOD

This systematic review identified relevant studies from the following sources: Medline, Cochrane database, cross referencing from identified articles, conference abstracts and proceedings, and guidelines published by the National Institute of Clinical Excellence (United Kingdom), Royal College of Obstetricians and Gynaecologists (United Kingdom), and American College of Obstetricians and Gynecologists.

RESULTS

A total of 451 articles and abstracts were reviewed. There was a wide variation in the reported incidence of anal sphincter muscle injury from childbirth, with the true incidence likely to be approximately 11% of postpartum women. Risk factors for injury included instrumental delivery, prolonged second stage of labor, birth weight greater than 4 kg, fetal occipitoposterior presentation, and episiotomy. First vaginal delivery, induction of labor, epidural anesthesia, early pushing, and active restraint of the fetal head during delivery may be associated with an increased risk of sphincter trauma. The majority of sphincter tears can be identified clinically by a suitably trained clinician. In those with recognized tears at the time of delivery repair should be performed using long-term absorbable sutures. Patients presenting later with fecal incontinence may be managed successfully using antidiarrheal drugs and biofeedback. In those who fail conservative treatment, and who have a substantial sphincter disruption, elective repair may be attempted. The results of primary and elective repair may deteriorate with time. Sacral nerve stimulation may be an appropriate alternative treatment modality.

CONCLUSIONS

Obstetric anal sphincter damage, and related fecal incontinence, are common. Risk factors for such trauma are well recognized, and should allow for reduction of injury by proactive management. Improved classification, recognition, and follow-up of at-risk patients should facilitate improved outcome. Further studies are required to determine optimal long-term management.

Correlation between anal sphincter defects and anal incontinence following obstetric sphincter tears: assessment using scoring systems for sonographic classification of defects

OBJECTIVE

To determine if there is a correlation between the sonographic extent of anal sphincter defects revealed by three-dimensional endoanal sonography (EAUS) and the degree of anal incontinence following primary repair of obstetric sphincter tears.

METHODS

This was a follow-up study of women who had suffered anal sphincter tearing during vaginal delivery at Aalesund Hospital between January 2002 and July 2004. Incontinence was assessed by St Mark's score. The anal canal was assessed with three-dimensional endoanal sonography (EAUS). Sphincter defects were classified according to the Starck score and our new EAUS defect score. The EAUS images were interpreted by an observer blinded to other patient data.

RESULTS

Sixty-one women were included in this study. Incontinence was reported by 32 (52%) women at a median of 21 (range, 9-35) months after delivery. Three-dimensional EAUS datasets were obtained in 55 women. There was a significant correlation between St Mark's score and our EAUS defect score (P = 0.034), and correlation approached but did not reach significance between St Mark's score and the Starck score (P = 0.053). There was a strong correlation between our EAUS defect score and the Starck score (P < 0.001).

CONCLUSIONS

There is a positive correlation between the extent of sphincter defects and the degree of anal incontinence following primary repair of obstetric sphincter tears. Our findings highlight the importance of adequate reconstruction of the anal sphincters during primary repair.

Selecting an outcome measure for evaluating treatment in fecal incontinence

PURPOSE

Various outcome measures exist to evaluate treatment in fecal incontinence, including descriptive, severity (fecal incontinence scoring systems), and impact (quality-of-life questionnaires) and diagnostic measures. We studied associations between changes after treatment for a number of outcome measures and compared them to patients' subjective perception of relief.

METHODS

We analyzed data of 66 patients (92 percent female; mean age, 62 years) (Vaizey score, Wexner score, two impact scales, utility, resting pressure, and maximal incremental squeeze pressure) at baseline and after physiotherapy. In a standardized interview by phone, we asked patients to compare their situation before and after treatment. Correlations between changes in outcome measures were calculated. These changes were compared with patients' subjective perception.

RESULTS

There was a high correlation between the changes in the Vaizey and the Wexner scores (r = 0.94, P < 0.01). Changes in Vaizey and Wexner scores correlated moderately with changes in maximum incremental squeeze pressure (r = -0.29, -0.30, both P < 0.05). Changes in utility and resting pressure were not correlated with changes in any of the other measurements (all r values between -0.086 and 0.18). Average severity scores (Vaizey and Wexner) were 1 point lower for patients who rated their situation as worse or equal (62 percent), 4 points lower for patients who reported their situation to be better (21 percent), and 9 points lower in patients who rated their situation much better (17 percent) (P < .05).

CONCLUSION

Severity measures are best related to patients' subjective perception of relief.